Background and purpose: Heavy metals cause major environmental pollution. They accumulate in soil, plants and crops through irrigation with polluted effluents or wastewaters. The aim of this cross-sectional study was to evaluate the concentration of lead and cadmium in soil and irrigation water and their accumulation in pith, flesh, and the skin of kiwifruit.
Materials and methods: A sample of one hundred kiwifruit, 15 soil and 25 irrigation water samples were randomly collected from the center, north, south, east, and west of a big kiwifruit garden located in north of Iran. Total concentrations of lead and cadmium were determined in all samples with furnace atomic absorption spectroscopy. Statistical analysis was performed applying ANOVA test in SPSS V10.1.
Results: The concentrations of lead in soil and flesh of kiwifruit were 33.74 and 2.93 and the concentrations of cadmium were 2.04 and 0.0026 mg/kg, respectively. The concentrations of lead and cadmium in irrigating water were 0.0044 and 0.0016 mg/L, respectively. There was a significant relation between the mean concentrations of heavy metals in the soil and that of the kiwifruit flesh. In areas with higher rate of lead and cadmium contamination the kiwifruits were found to be significantly more contaminated (P<0.05). The mean concentration of these heavy metals in irrigation water were lower than national and international threshold levels.
Conclusion: Heavy metal contamination in soil and the cross relation between irrigation water and soil, calls for appropriate monitoring of such a valuable fruit and routine environmental controls are highly necessary.